The Google Glass project sounded very interesting when it was incepted. Once it's released out to the public some time this year it would be great to try and play with the device itself but so far all information that I have at my disposal comes from various publishings on the internet.
Looks like the biggest concern with this device would be its security and privacy of others. The neat and very cool "instant" camera feature that captures things as you go and that you don't have to press buttons to turn it on is a great idea. However, it most likely will make others uncomfortable when they see you wearing the headset as there is no red light indicator that recording is on.
Price point of $1,500? I don't think this is going to be anywhere as popular as iPhone. If Google makes it sub $300, than maybe.
Battery life will most likely be another issue. There is no new innovations in the battery field that could make the device go for entire day without a recharge.
Applications for the prototype version seem to be Android based with a very basic feature set and mostly going to be geared towards "intuitive search" and "on time" information based on location, context or camera input.
Intersog software development company is planning to create new apps for google glass support.
Overall, this is a beta prototype product with an intention to gauge how acceptable the social environment is going to be and how well perceived the use of this device would be among average consumers. If you look at the pictures of people wearing one, they do look dorky and geeky.